I’d like to use this as a complement to Renovate which already does this, as per:

• https://docs.renovatebot.com/modules/manager/github-actions/

I.e. “just” change the comment you make from:
# pin@0.4.0
…into:
# 0.4.0

Thus I could use Renovate for:

• Upgrade to new versions
• Pin any non-pinned in master/main

And use this action for:

• Pin any non-pinned in open PRs

Would you be open to this?

Possibly configurable if changing the defaults for this breaks any consumers…?